Match Each the Situation That Illustrates It with Type of Extraneous

Match each the situation that illustrates it with type of extraneous variable that threatens the internal validity of an experiment.
-Students below the 15th percentile in reading achievement who volunteer are placed in the experimental group, and nonvolunteers at the same reading level are placed in the control group.

A) History
B) Maturation
C) Testing
D) Experimental treatment diffusion
E) Statistical regression
F) Differential selection
G) Experimental mortality